Stainless False Bottom

[Ash in Perth]

Gday.
Im having a bit of trouble trying to find/design a decent flase bottom for my SS keg mash tun. Tap will be below the screen and it will have to be about 25-30cm across (10-12"). Ive seen 'phils phalse bottoms' but they have a hole i would need to block and are quite pricey, plus the holes are a little bigger than i would like. I have enough SS mesh to cover the bottom, but it must stay above the bottom and be removable.

Cheers for any suggestions!

 

[Andyd]

I use one of Phils SS false bottoms in a similar setting and I've had great results - my rew buddy said he's never seen run off come out so clear.

I have my tap above, and use a copper pipe connection to the spiggot (pitty about the kink, but it doesn't seem to have an adverse effect on the flow rate ,and keeps the screen nice and cosy on the bottom of the vessel even when you're banging your mash paddle around.
(This was post brew - excuse the floaties )

 

[mika]

Having the tap above doesn't stop you from draining all the precious brew out does it ?

 

[Ash in Perth]

it would but if you sparge enough all you would be leaving behind is water.

 

[mika]

I'm no AG expert, but if you're sparging down that low aren't you running the risk of extracting tannins ?

 

[Ash in Perth]

you would still stop when the runnings out the tap are dry enough as you would if the tap was on the bottom. I dont think enoguh would be lost to make a real impact.

 

[goatherder]

I've got one of the SS false bottoms in the pic above. It's a bloody ripper. It only cost me about $40-$45, well worth it I reckon, I wouldn't muck around with any other solution. It's the same as the ones at G&G I think. I got it from my LHBS.

Just get a couple of brass fittings from bunnings (an end cap and something to screw it into) to seal up the hole.

Also, get a longish 3/16" bolt and drill up through the bottom of the tun and the false bottom. Fix the bolt in the bottom of the tun with some washers and silicone seals to make it watertight. Then you can use a wingnut to fix the false bottom tight to the bottom of the tun. And it's easily removable. I haven't got a good pic of it, but let me know if you want one. I'll take one in the morning before I start brewing.

 

[dicko]

If the outlet tube from the tap is lower than the bottom of the keg (tun) then the wort will syphon untill the pick up pipe which is under the false bottom becomes exposed due to the level being lower than its end.
I used to use a false bottom in a keg for a mash tun with the outlet pipe being fitted to the bottom of the keg. It worked really well except that when the run off got to the last half litre or so some grain particles would come through into the kettle. I dont know what caused this and I have since gone to a keep cold cooler with a manifold. AH!! Perfect!! and happy although nothing really wrong with the keg set up it was hard to maintain mash temps over an hour or so.
Cheers

 

[Ash in Perth]

Dont worry about a pic mate, i know what you mean. Its a good idea. Im going to try and stick with SS but i could probably make something similar using SS nuts/bolts etc.


Cheers.

 

[JasonY]

Ash I believe TWOC has these SS false bottoms, I got one a month back which was about the size you are after. Can't remember how much $40 - $50 probably. Only had a chance to use it once so far and I need to mount it better in my rubbermaid but it worked well.

 

[Ash in Perth]

I spoke to Roy today and they have them from $40-$50 for the different sizes. He has built something similar to what goatherder has made so ill check that out when im there next.

Id prefer to build my own out of finer mesh but ill buy one if i cant figure out how to make a good one. Any home made false bottom success stories out there?

Cheers guys!

 

[razz]

G'day Ash. I made one about 10 years ago when I cut up a 50 lt ss keg to make into a mash tun. I cut the top 1/3 out of the keg with an angle grinder then turned it over and slipped it into the bottom of the remaining keg. With a little bit of edge grinding this became a very snug fit, I then spent approx 3 hours drilling several hundred holes in this new false bottom. From memory I used a 2 or 3mm drill bit. I used this setup for several years until I rebuilt my system and went for a 1/2" copper manifold. I still use the same mash tun with the copper. If I had my druthers I would go the copper manifold any day.
PS. I believe ss braided hose does just as good a job !

 

[Crazy]

I spoke to Roy today and they have them from $40-$50 for the different sizes. He has built something similar to what goatherder has made so ill check that out when im there next.

Id prefer to build my own out of finer mesh but ill buy one if i cant figure out how to make a good one. Any home made false bottom success stories out there?

Cheers guys!

Ash

We originally did the same as Razz with the top of a keg with a few million holes (500 odd). We use a Hermes system and had trouble with a stuck grain bed while doing step mashes.

We have just done a prototype out of 1.8mm perforated s/s mesh. When we remodel the brewery in the near future we will have a ring around the edge of the tun at the bottom and a couple of wing nuts to hold a flat false bottom down, but for now this works a treat.

On a different note I feel a lot of the problem with slow runnings while trying to raise the temp of the mash is caused by the height to width ratio of the mash tun. I had a look back at the drawings from one of the commercial brewhouses I worked on during installation and they have a very wide and not to deep grain bed in there lauter tun (sorry can't remember exact dimensions). Our 50l squat keg has a grain height almost twice the width of the tun. Our new system will hopefully be different if we can find a suitable vessel.

Oh by the way I am not to crap on the Tig but kept putting little holes in the mesh when I tried to weld it so we took it into the sheeties and they had the same problem. Spot welding is defiantly the go. We also tried this with a 3mm hole size mesh and had problems with too much crap coming through before the grain bed set and the first few steps were very cloudy with grain bits.

Regards Derrick

 

[MHB]

The best false bottom you cam make is wedge wire ideally 0.8-1.2 mm gap. Wedge wire is now used in almost all small commercially made small breweries. The big advantages of wedge wire are that it is harder to block up, has a high void to surface area (around 1:3), and is strong enough to be self-supporting in most applications, being dead flat doesnt hurt either.

There is a pretty straight forward relationship between bed depth and lautering speed; and an inverse relationship between bed depth and its filtering ability.

So
Deep beds filter better and slower.
Shallow beds run faster but its harder to get clear wort.

Its a compromise, in a commercial application speed is often the prime driver beds are down around 300mm. in old traditional English ale house breweries beds were up to 2 meters deep.

As you drain down the bed starts to collapse under its own weight, the grain starts to move around and some gets loose and travels with the sparge water.
When the grain bed is exposed, you could catch any cloudy runnings and recirculate them in small portions until it is running clear again.

MHB

 

[Ash in Perth]

Thanks for the advice. Its going to be a herms system so it doesnt matter if the first runnings are cloudy, it will be re-cirulating the whole time and so by the time i sparge the runnings should be fairly clear.

What is wedge wire?

I have some fine, woven mesh but that is flimsy and would need a really well supporting frame to hold it.

The mash will be about as deep as it is wide because ill only be doing ~23L batche4s still.

 

[vlbaby]

i've had a lot of troubles with stuck sparges lately especially since i have gone to a herms system, so the s/s false bottom is the way i'm going next. This is hopefully my first attempt at a false bottom. It is a 2mm thick piece of s/s that has been laser cut with a series of 1.8mm slots cut into it. The plan is to have the wort drain from the lowest point of the tun, and have a threaded rod protrude into the centre of the false bottom with a locknut to hold it into place.
I'll probably will make increase in diameter of about 50mm for the final product.
Anyhow this is it.....


cheers


vl.

 

[Ash in Perth]

thats cool. where and how did you get that made up?

 

[vlbaby]

thats cool. where and how did you get that made up?

I had it made up by one of my customers who does laser cutting. I have no idea what it would actually cost to have made if i had to pay for it. Furthermore I have no idea as yet even if it will work. I'll keep you posted if all goes ok.

vl.

 

[MHB]

View attachment 7833

shaped wire like this
best thing going

MHB

 

[Ash in Perth]

Any idea where i can get a 25cm diameter sheet of that stuff MHB?